1. Technical Field
The present invention relates to a technique for correctly identifying an apparatus using a fluid, by capturing changes in a flow rate of a fluid.
2. Description of the Related Art
A gas meter described in connection with Patent Document 1 has hitherto been available as a gas meter that identifies a working appliance in a fluid pipe system having a gas meter. As shown in FIG. 11, a gas meter 1 described in connection with the document is made up of a flow rate measurement unit 3 that is disposed in a flow path 6 connected to a household gas supply pipe and that measures a gas flow rate at a given time interval; a computation unit 4 that determines a difference value of flow rate values output from the flow rate measurement unit 3; and a comparison determination unit 7 that compares the difference value computed by the computation unit 4 with a change determination value registered in a storage unit 5, to thus determine a change in a working state of the gas appliance. The computation unit 4, the comparison determination unit 7, and a gas shutoff valve 2 are controlled by a control circuit 8.
In the gas meter 1, a change in a difference value of an instantaneous flow rate output from the flow rate measurement unit 3 is consecutively computed, and a change in working state of the gas appliance is determined by the amount of change. Registered data are compared with the measured change in gas flow rate (the difference value), thereby enabling identification of working gas appliances 13, 14, and 15.
Patent Document 1: JP-A-2006-313114